Tool holder assembly for a portable power tool

Abstract

A toolholder assembly incorporated in a portable power tool having a housing and a drive disposed therein. The assembly includes a toolholder body, a first releasable securing arrangement for attaching the toolholder body to the drive for oscillating the toolholder body in a longitudinal direction; a second releasable securing arrangement at the front end of the toolholder body for attaching a tool bit to the toolholder body, longitudinal guide faces provided on the toolholder body between the two releasable securing arrangements and a bearing member mounted in the housing and provided with longitudinal counterguide faces which slidably cooperate with the longitudinal guide faces of the toolholder body for taking up forces transverse to the direction of the longitudinal oscillation of the toolholder body.

What is claimed is: 
     
       1. A toolholder assembly incorporated in a portable power tool having a housing and a drive means disposed therein comprising in combination: (a) a plastic toolholder body having a front end for carrying a tool bit;   (b) a first clamping assembly at a rear end of the toolholder body for releasably securing the toolholder body to the drive means for oscillating the toolholder body in a longitudinal direction by the drive means; said first clamping assembly including (1) a first clamping yoke and   (2) a first tightening screw carried by said first clamping yoke;     (c) a second clamping assembly at said front end of said toolholder body for releasably securing a rear shank of the tool bit to said toolholder body; said second clamping assembly including (1) a second clamping yoke and   (2) a second tightening screw carried by said second clamping yoke;     (d) longitudinal guide faces provided on said toolholder body between said first and second releasable securing means; and   (e) a bearing member mounted in said housing and provided with longitudinal counterguide faces slidably cooperating with said longitudinal guide faces of said toolholder body for taking up forces transverse to the direction of the longitudinal oscillation of said toolholder body.   
     
     
       2. In a toolholder assembly incorporated in a portable power tool having a housing and a drive means disposed therein; the assembly including a toolholder body having a front end for carrying a tool bit; first releasable securing means at a rear end of the toolholder body for attaching the toolholder body to the drive means for oscillating the toolholder body in a longitudinal direction by the drive means; the improvement wherein said toolholder body has a T-shaped cross section along a length portion thereof; the improvement further comprising (a) second releasable securing means at said front end of said toolholder body for attaching a rear shank of the tool bit to said toolholder body;   (b) longitudinal guide faces provided on said toolholder body between said first and second releasable securing means; said longitudinal guide faces being situated in four planes defining the enlarged part of the T-shaped cross section; and   (c) a bearing member mounted in said housing and provided with longitudinal counterguide faces slidably cooperating with said longitudinal guide faces of said toolholder body for taking up forces transverse to the direction of the longitudinal oscillation of said toolholder body.   
     
     
       3. A toolholder assembly as defined in claim 1 or 2, wherein said toolholder body is a thermoplastic. 
     
     
       4. A toolholder assembly as defined in claim 2, wherein said thermoplastic is nylon-6,6. 
     
     
       5. A toolholder assembly as defined in claim 2, wherein said first and second releasable securing means comprise, respectively, first and second clamping assemblies. 
     
     
       6. A toolholder assembly as defined in claim 5 or 1, wherein each said clamping assembly comprises a clamping sleeve forming terminal portions of said toolholder body; each said clamping sleeve being provided with at least one throughgoing radial slot for receiving tool bit shanks of flat cross section. 
     
     
       7. A toolholder assembly as defined in claim 5, wherein each said clamping assembly comprises a clamping yoke and a tightening screw carried by the respective clamping yoke. 
     
     
       8. A toolholder assembly as defined in claim 1, wherein said toolholder body has a T-shaped cross section along a length portion thereof; said longitudinal guide faces are situated in four planes defining the enlarged part of the T-shaped cross section. 
     
     
       9. A toolholder assembly as defined in claim 8 or 2, wherein said bearing member has a generally C-shaped cross section surrounding said enlarged part. 
     
     
       10. A toolholder assembly as defined in claim 8 or 2, wherein said first and second releasable securing means comprise, respectively, first and second clamping sleeves forming terminal portions of said toolholder body and further wherein the length of each said guide face is at least one half the length of the entire said toolholder body.